Muzan's telepathic powers leave other demons' thoughts open to him just by catching sight of them. He can speak to them in their heads even when they are far from him. Although his range is somewhat limited, he can also locate them with this connection and feel what they feel.
Demonic Blood: After the experimental treatment gave him a new body and physiology, Muzan's blood develops special mutagenic properties that can transform humans into creatures known as demons.
Demon Body: Unique from other demons, he possesses seven hearts, and five brains.
Kokushibo was the strongest swordsman and considered as the strongest member of the Twelve Demon Moons and the second strongest demon after Muzan Kibitsuji.
Yoriichi Tsugikuni was the first Demon Slayer and also the one who invented Breathing Techniques in the first place. Yoriichi was born with the Demon Slayer mark and prowess in swordsmanship. His powers were beyond comparison as he defeated Muzan once and had him on the verge of death until he managed to escape.
After he neutralizes Tamayo's poison and emerges from his flesh cocoon, Muzan's hair grows in length and turns white due to Shinobu's poison accelerating his age. He also grows numerous mouths all over his limbs, each one lined with a set of incredibly sharp fangs.
Muzan Kibutsuji was born during the Heian Era of ancient Japan to a noble family. Ever since he was in his mother's womb, Muzan was extremely frail and weak.
Tsukito, Yorogi, Kuraku, and Isatsu all agree that they are loyal to Muzan.
The warrior Muzan feared was a swordsman named Yoriichi Tsugikuni. Yoriichi was the only slayer before Tanjiro who came close to killing Muzan, and the flashback of their fight occurred in Chapter 187.
The only reason why Muzan hates Doma is because of his insincerity and lack of emotions. This might sound odd, expecting emotions from a demon, but even a demon has to retain such tendencies to keep things in order.
For those who have watched only the first season of the anime, they will be surprised to know that Muzan turns into a woman in the second season. He keeps transforming in order to hide his true identity, and he's even known to change into an 11-year-old child to hide from Demon slayers.
The two known demons who broke free of Muzan's curse are Tamayo and Nezuko. Tamayo was able to break free of the condemnation when Yoriichi fought Muzan, nearly killing him in the process. During this weakened state, Yoriichi let Tamayo go, free her from Muzan, and free her from the curse.
Akaza was also one of Muzan's favorite demons out of all his subordinates. The reason behind this is Akaza's extreme loyalty to his master. The Upper Rank Three demon was always sent away on special missions, something the Upper Rank 1 and 2 were often denied of.
History. Muzan was born in Japan's Heian era, to a constant struggle to survive on account of his frailty. His heart stopped multiple times in his mother's womb, and when he first entered the world, he was deemed stillborn, having no pulse and not breathing.
Haruka Shiraishi: Muzan's Daughter.
Muzan's loyal wife and daughter seem like convenient test subjects to help him synthesize a cure for sunlight weakness as a backup in case the Blue Spider Lily is never found. The young girl might even be Muzan's biological child, a half-demon who gives off the scent of a human while having his essence in her.
Muzan's Blood Demon Art is known as “Biokinesis.” It allows him to alter his body and shapeshift at will. Although all demons have this innate ability, Muzan elevates it by modifying his flesh and organs. Biokinesis is also the only reason Muzan has been able to hide from the Demon Slayer Corps for 1000 years.
It's true that in later episodes, Muzan also appears as a woman wearing a kimono when he's holding court over other Demons, most of whom are also wearing traditional Japanese clothing. This might have something to do with Demons (or “Oni”) themselves being part of traditional Japanese culture.
Like most other demons, Muzan started out as a human, but since he was the first, there wasn't simply a demon who could give him blood and cause him to transform.
11. The demon slayers successfully defeated Muzan.
1 Muzan (Demon Slayer)
Without that antidote, it would have been impossible to kill him. So despite all her strength and humanity, Nezuko would have easily lost to Muzan.
Muzan may be strong, but Madara is on a whole other level. Madara has Sharingan, Rinnegan, and wood-style jutsu, while Muzan just has some fancy demon powers. He could easily read Muzan's moves with Sharingan, then use wood-style jutsu to pin him down.